This application claims the priority of German Application No. 198 55 535.0 filed Dec. 2, 1998, which is incorporated herein by reference.
This invention relates to a spin-stabilized artillery projectile having a driving guide band and a plastic sealing ring circumferentially surrounding the projectile and being seated thereon. The driving band has at least one circumferential groove.
A projectile of the above-outlined type is disclosed in German Patent No. 40 00 167 to which corresponds U.S. Pat. No. 5,081,931. The projectile described therein has a driving band which is provided with a plurality of annular grooves and further has a plastic sealing ring disposed rearwardly of the driving band. The sealing ring which is also referred to as an obturator ring, serves for improving the seal of the projectile against the high-pressure propellant gases and is, as a rule, secured to the projectile by friction obtained by fit-shrinking.
It is a disadvantage of the above-outlined projectiles that the sealing ring can be easily damaged or destroyed by mechanical effects. Damaged or loosely sitting sealing rings are, during the loading process, readily stripped from the projectile which involves safety-related problems for the entire weapon system. It has further been found that the sealing rings are frequently lost from the projectile during transport thereof because their bias diminishes or disappears as the plastic material of the sealing ring ages.
Conventional projectiles having a plastic sealing ring arranged rearwardly of the driving band cannot be used in up-to-date large-caliber weapons (such as tank howitzers) which operate with an automated ammunition flow.
It is an object of the invention to provide an improved spin-stabilized artillery projectile of the above-outlined type in which the sealing ring, while fully preserving its sealing function, is securely prevented from damage or destruction or from being stripped from the projectile during introduction thereof into the loading chamber of the weapon.
This object and others to become apparent as the specification progresses, are accomplished by the invention, according to which, briefly stated, the spin-stabilized projectile includes a projectile body having a longitudinal axis; a metal driving band mounted on the projectile body and having a circumferential groove surrounding the axis; and a plastic sealing ring seated in the groove and affixed to the projectile body.
It is an essential principle of the invention to embed the sealing ring in a circumferential groove of the driving band rather than arranging it rearwardly of the driving band. Such an arrangement reliably protects the sealing ring against damage and practically excludes the possibility of the sealing ring being stripped from the projectile.
The defined seat of the sealing ring in the circumferential groove of the driving band ensures an improvement and a higher reliability of the sealing function and also results in a reduction of the weapon barrel wear.
Further, existing projectiles which are, because of their rearwardly arranged sealing ring, not adapted for use in up-to-date automatic weapon systems may be readily retrofitted with the arrangement of the invention in a suitable manner. In such a case it is only required to axially widen, if necessary, the already existing groove in the driving band and to insert the sealing ring into the groove and, if required, frictionally connect the sealing ring with the projectile.